{ "id": "1010.2536", "version": "v2", "published": "2010-10-12T23:31:14.000Z", "updated": "2011-08-30T04:38:17.000Z", "title": "Typicality of normal numbers with respect to the Cantor series expansion", "authors": [ "Bill Mance" ], "comment": "16 pages", "journal": "New York J. Math. 17 (2011), 1-17", "categories": [ "math.NT" ], "abstract": "Fix a sequence of integers $Q=\\{q_n\\}_{n=1}^\\infty$ such that $q_n$ is greater than or equal to 2 for all $n$. In this paper, we improve upon results by J. Galambos and F. Schweiger showing that almost every (in the sense of Lebesgue measure) real number in $[0,1)$ is $Q$-normal with respect to the $Q$-Cantor series expansion for sequences $Q$ that satisfy a certain condition. We also provide asymptotics describing the number of occurrences of blocks of digits in the $Q$-Cantor series expansion of a typical number. The notion of strong $Q$-normality, that satisfies a similar typicality result, is introduced. Both of these notions are equivalent for the $b$-ary expansion, but strong normality is stronger than normality for the Cantor series expansion. In order to show this, we provide an explicit construction of a sequence $Q$ and a real number that is $Q$-normal, but not strongly $Q$-normal. We use the results in this paper to show that under a mild condition on the sequence $Q$, a set satisfying a weaker notion of normality, studied by A. R\\'enyi in \\cite{Renyi}, will be dense in $[0,1)$.", "revisions": [ { "version": "v2", "updated": "2011-08-30T04:38:17.000Z" } ], "analyses": { "subjects": [ "11K16", "11A63" ], "keywords": [ "cantor series expansion", "normal numbers", "real number", "similar typicality result", "lebesgue measure" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1010.2536M" } } }